Strain-insulator.



NETE@ STATES rfi "ri if@ ad diluida@ THEDORE VARNEY, OF PITTSBURG, ANDEDY/JARD ERNEST ROSE, GF SViTSSVLE,

PENNSYLVANIA, ASSIGNORS, BY MESNE ASSIGNMENTS, TO iESTINGHOUSE-ELEG-- TRIC @c MANUFACTURNG COMPANY, @F EAST PITTSBURG, PENNSYLVANA, A CGR-"PORATIGN OF PENNSYLVANIA.

STRAIN-INS'ULATOE.

T 0 all 'whom it may concern.'

Be it known that we, Trnononn VARNEY and EDwAnnEnNns'r Ross, citizens ofthe United States, 'and residents, respectively, of Pittsburg andSwissvale, in the county of Allegheny and State of Pennsylvania, haveinvented a new and useful improvement in Strainlnsulators, oi which thefollowing is a specification.

Ourinvention relates to strain insulators for electric lines, and it hasfor its object te provide a device of this character that shall becompact and durable in construction., easy to assemble and capable ofwithstanding strains incident tothe use of high voltages,

'Figure l of the accompanying drawings is a sectional elevation or adevice constructed. in accordance with our invention, and Fig. 2 is adetail View of one of the parts shown in Fig. 1.

Referring to the drawings, the device here illustrated comprises a pairof similar trusteconical rnetal tubes l and 2 having correspendingscrew-threaded cylindrical projections 3 and Li, a common sleeve 5. intowhich. the projections 3 and i are screwed, insulating tubes (i and Iseated inthe first-named truste-conical tubes, tapered plugs 8 and 9seated in the insulating tubes, and molded insulating jackets l() and ilon the metal tubes l and 2. The outer surfaces of the metal tubes l and2 are preferably corrugated in' order that the molded 'insulatingmaterial of which the jackets are composed may more readily adherethereto, and the outer surfaces oit the jackets are corrugated in orderto increase the surface or current creepage distances be tween therated.

The plugs 8 and 9 are provided with pro* 4jections l2 and 13wliichiextend outwardly and are preferably in the forr'n of bolts, theirouter extremities being); screw-threaded to receive strain-loops la andl5.

in assemblingI the device, the metal tubes l and 2 are iii-st providedwith the insulating jackets vl0 and il which are formed by a well knownmolding processunder the action of high pressures. lin the deviceillustrated, the insulating jackets project for ma terial distancesbeyond the extremities of the metal tubes and constitute sleeves 16 and17.

Specification of Letters Patent.

Application led. January 10, 1908.

parts-which are electrically sepa- 'Pat-ented @et 26, ttig.

Serial No. 410,224.

L@ plugs 8 and 9, set-nuts 18 being employed to close the outer ends ofthe sleeves l@ and it'. in this way, the insulatingl tubes ti and whichare largely depended upon for taining adequate electrical separationbetween tbe loops ifi and 15, are real'. nd protected from the weather,'mm n are provided with cylindrical c* so they may iit into the sie s oand are provided with iioies it? 'to receive .a spannerA wrench. Themetal sieevr i 2 are provided ith annular projections 2G and 2i havingholes 22 suitably iocated to receive a spanner wrench in order that thetwo baives oi the device mi: f be easily joined. together and separatedeach other, 1

life desire that our invention shaii i strued to cover variousstructural tions and that only sucia. iiniitation imposed as areindicated in the a claims.,

W' e claini as our invention:

i. A. strain insulator comprising duplicate members tbe adjacent innends of which abut against each other are plo vided with externalscreuti i and coupling sleeve into which the s. screwed.

Qfifa strain insulator comprisn plicate metal tapered tubes the inneradjacent ends oit which abut against each other and are provided withexternal screwthreads, a coupling sleeve into which said ends arescrewed, and tapered plugs seated in and insulated from the tubes.

A strain insulator' comprising two du- Llicate trusto-conical metaltubes having cyiindrical abutting projections provided with externalvscrew-threads, a couoling sleeve into which. said parts are screwed,tapered CSO

